In non-stick skillet, heat olive oil over medium heat about 2 minutes.
Add chicken and cook about 6 minutes. Turn chicken, add onion and cook
about 6 minutes more or until onion is clear and chicken is tender.
Remove from heat. Cut chicken into thin slices across grain of breast;
place in bowl. Add sauteed onion; sprinkle with salt and pepper, mixing
carefully. Add vinegar and chives; mix well.
In small bowl, mix together yogurt and cucumber. On each piece of pita
bread, spread 2 tablespoons yogurt-cucumber sauce. Then place 1/4 of
chicken mixture on each pita bread; fold in half, wrap in plastic wrap and
chill in refrigerator at least 2 hours. Repeat for remaining sandwiches.
Makes 4 servings (2 wedges each).
NOTE: For a picnic, place sandwiches in an ice chest or insulated
container until serving time. Cut each sandwich in half to serve.